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Mini Shell
Mini Shell
from sympy.core import S, symbols
from sympy.matrices import eye, Matrix, ShapeError
from sympy.matrices.expressions import (
Identity, MatrixExpr, MatrixSymbol, Determinant,
det, ZeroMatrix, Transpose
)
from sympy.matrices.expressions.special import OneMatrix
from sympy.testing.pytest import raises
from sympy import refine, Q
n = symbols('n', integer=True)
A = MatrixSymbol('A', n, n)
B = MatrixSymbol('B', n, n)
C = MatrixSymbol('C', 3, 4)
def test_det():
assert isinstance(Determinant(A), Determinant)
assert not isinstance(Determinant(A), MatrixExpr)
raises(ShapeError, lambda: Determinant(C))
assert det(eye(3)) == 1
assert det(Matrix(3, 3, [1, 3, 2, 4, 1, 3, 2, 5, 2])) == 17
A / det(A) # Make sure this is possible
raises(TypeError, lambda: Determinant(S.One))
assert Determinant(A).arg is A
def test_eval_determinant():
assert det(Identity(n)) == 1
assert det(ZeroMatrix(n, n)) == 0
assert det(OneMatrix(n, n)) == Determinant(OneMatrix(n, n))
assert det(OneMatrix(1, 1)) == 1
assert det(OneMatrix(2, 2)) == 0
assert det(Transpose(A)) == det(A)
def test_refine():
assert refine(det(A), Q.orthogonal(A)) == 1
assert refine(det(A), Q.singular(A)) == 0
def test_commutative():
det_a = Determinant(A)
det_b = Determinant(B)
assert det_a.is_commutative
assert det_b.is_commutative
assert det_a * det_b == det_b * det_a
Zerion Mini Shell 1.0